Here is another example of a high voltage application where intermediate rails are being used. The common input rail in industrial applications are 42V, 36V or 24V. These rails normally see a peak voltage which is 15% to 25% higher than the nominal voltage. There are three different reasons this input voltage variation occurs: 1) Poor power source, 2) Fully charged battery voltage is higher than the nominal voltage, and 3) Voltage spike occurs when load is disconnected and the spike value depends on source quality and input capacitor. In addition, these types of customers want an extra margin of safety. For a 24V battery system, an input requirement of 42V is very common. This slide shows an example block diagram of an ultrasound machine, which uses an input rail of 24V or 36V along with a battery backup system. They typically have 20 to 25 power rails. Three to four rails are high power rails to drive DSPs, CPUs and FPGAs. In general, the input rail is first converted to 12V and/or 5V rails. The ISL8117/A and other high voltage products are well suited for these applications. They use different power topologies such as buck, boost, LDO, display drivers, and simple voltage inverters among others.